Lakes Entrance Sand Management, Environment Protection, Sand Dredging, Tide Information, Dredging Pump Sand, Coastal Environment & Coastal Protection, Gippsland

Reports & Plans

CURRENT PLANS & REPORTS

Lakes Entrance bar and Channel Dynamics

Created: 16 December 2003

Download 1779.53 Kb

Coastal Engineering Solutions Pty Ltd (CES) has been engaged by the Gippsland Port Authority to undertake an assessment of how the offshore bar (the Bar) and navigation channels at Lakes Entrance would respond to the following management options:
1. Discontinue all maintenance dredging on the Bar.
2. Maintain the status quo, ie continue with current dredging methods and the use of the Sand Transfer System to dispose of the dredge spoil from the internal channels to the beach at least 1 kilometre east of the entrance.
3. Installation of a bi-directional sand by-passing system at the Entrance - with all spoil being disposed of 1 km (or more) to the east or west of the Entrance.
4. Remove all or part of the Bar. The total entrance bar volume is estimated to be approximately 15 million cubic metres. That is, about 15 million cubic metres of sand has accumulated on the foreshore and offshore of the entrance since it was first established in 1889. Prior to the opening of Lakes Entrance, the beach and offshore contours were straight and roughly parallel to the shoreline. The plan alignment of the beach and that of the offshore contours now have a curvature. Much of the Bar can be removed if about 3 million cubic metres of sand was to be dredged. Consider the removal of this amount of material.
5. Reduce the general bar level to -5 metres. The objectives of this option are to dispense with the day-to-day maintenance dredging of the Bar channel and to address the progressive restriction to port access by periodic Bar reduction using external dredging services.
6. Maintenance of a deeper channel through the bar and into Cunninghame Arm. Presently, the maintenance dredging regime aims to provide a three metre deep channel.
7. Consider the general impact on all options of installing a bi-directional by-passing system at the Entrance - with all spoil being disposed of 1 km (or more) to the east or west of the Entrance.